Who's firing rockets from Sinai? asks Michael Dunn, and it's a good question. The Egyptians, saying their border with Israel is heavily monitored, first said no but then implied Palestinian groups were in fact launching them from Sinai by launching a sweep. The Jordanians, who are on the receiving end of many of these rockets that appear to aimed at the Israeli port of Eilat, claim to have proof they're coming from Egypt but haven't divulged it. The Israelis blame "the Khamas" and Hamas calls Egypt's allegation that Palestinian groups may be involved "unprofessional" and without evidence. The speculation in the Cairo papers — based on security sources — that a Palestinian group with an indirect affiliation with Hamas may be responsible.
It's all rather confusing, but assuming the rockets were fired from Sinai there is another alternative: that we are seeing the revival of the Palestinian / Bedouin groups that operated in the Sinai over the last decade and are believed to be responsible for the 2004-2006 wave of bombings of tourist destinations in the Peninsula. Or a new radicalization of purely Bedouin groups in the area. Or Palestinian militants going into Sinai from Gaza through the tunnels. That's for the whodunnit. There's also the question of where did they get these rockets from? Are they part of the arsenal allegedly being smuggled into Gaza from Egypt, or smuggled from Gaza into Sinai? No matter where you stand on the question of the anti-smuglling wall, this incident will lend credence to the arguments that having Sinai as a trans-shipment venue for weapons to Gaza adds proliferation risks to Egypt itself.
Also, although it's an outlier, perhaps one should not dismiss the idea that these rockets may not be unrelated to the general unrest among Sinai's Bedouin population, which has seen disgruntled groups block roads and attack tourism sites in the last month. Egypt's Sinai problem has been a slowly brewing mix of problems for a good decade now, and the regional situation only adds to it.